1. Field
The present disclosure relates to network management. More specifically, the present disclosure relates to a method and system for efficiently managing multicast routing over multi-chassis trunks.
2. Related Art
The exponential growth of the Internet has made it a popular delivery medium for multimedia applications, such as video on demand and television. Such applications have brought with them an increasing demand for bandwidth. As a result, equipment vendors race to build larger and faster switches with versatile capabilities, such as multicasting, to move more traffic efficiently. However, the size of a switch cannot grow infinitely. It is limited by physical space, power consumption, and design complexity, to name a few factors. Furthermore, switches with higher capability are usually more complex and expensive. More importantly, because an overly large and complex system often does not provide economy of scale, simply increasing the size and capability of a switch may prove economically unviable due to the increased per-port cost.
As more time-critical applications are being implemented in data communication networks, high-availability operation is becoming progressively more important as a value proposition for network architects. It is often desirable to aggregate links to multiple switches to operate as a single logical link (referred to as a multi-chassis trunk) to facilitate load balancing among the multiple switches while providing redundancy to ensure that a device failure or link failure would not affect the data flow.
Currently, such multi-chassis trunks in a network have not been able to take advantage of the multicast functionalities available in a typical switch. Individual switches in a network are equipped to manage multicast traffic but are constrained while operating in conjunction with each other for providing a multi-chassis trunk. Consequently, an end device coupled to multiple switches via a multi-chassis trunk typically exchanges all the multicast data with only one of the switches. If the switch fails, another partner switch can forward multicast data traffic to the end device only after the partner switch becomes part of the multicast distribution process. As a result, the failure recovery becomes inefficient. Furthermore, other routing devices in the network can send data to that end station only via one of the switches to which the end station is coupled.
While multi-chassis trunk brings many desirable features to networks, some issues remain unsolved in multicast routing.